1. Field of the Invention
The present invention relates to an ash-collecting and exhaust device, and more particularly to an ash-collecting and exhaust device for a grain dryer that may prevent ashes or impurities from accumulating in and damaging a fan unit of the ash-collecting and exhaust device, may prevent a driving motor from producing high temperature due to the ashes or impurities during operation, and may prolong the life of the ash-collecting and exhaust device, reduce the cost of use, and may collect the ashes or impurities repeatedly to provide an air-cleaning effect to the ash-collecting and exhaust device.
2. Description of Related Art
Grains such as rice, wheat or coffee beans need to be processed by a shelling process, and the husks that are shelled from the grains can be used as biomass fuels for a conventional grain dryer. A heat source that is generated by burning the biomass fuels in a conventional grain dryer may be used to dry or adjust the moisture content of the grains, and this may achieve an effect of resource recovery and reuse. The conventional grain dryer has an ash-collecting fan device to collect ashes or impurities in the air that exhausts from the conventional grain dryer to reduce pollution and provide clean air for use.
The ash-collecting fan device of the conventional grain dryer has a body, a driving motor, and a fan. The body is a hollow casing and has two ends, an air inlet, and an air outlet. The air inlet and the air outlet are respectively formed in the two ends of the body. The driving motor is mounted in the body between the air inlet and the air outlet. The fan is mounted in the body, is connected to the driving motor between the air inlet and the driving motor, and is rotated relative to the body by the driving motor. When the fan is rotated by the driving motor relative to the body, air that contains ashes or impurities may flow into the body via the air inlet. When the air flows into the body, the body has at least one guiding plate formed in an internal surface of the body to enable the air to flow as a centrifugal wind, and this may enable the ashes or impurities in the air to accumulate on the internal surface of the body. Then, the ashes or impurities in the air may be reduced when the air flows out of the ash-collecting fan device.
Although the ash-collecting fan device may provide an ash-collecting and air-cleaning effect to the conventional grain dryer, the ashes or impurities are accumulated on the internal surface of the body by the centrifugal wind that is formed by the fan and the at least one guiding plate of the body. In order to prevent the fan from breaking or damage during rotation since the structural strength of the fan is insufficient, the ash-collecting fan device has an annular strengthening rib connected to blades of the fan to improve the structural strength of the fan. However, the ashes or impurities in the air may be accumulated on positions between the blades and the strengthening rib, and the fan may be vibrated and damaged during the rotation process by the accumulated ashes or impurities after a long time of use.
In addition, the driving motor that is mounted in the body may be affected by the ashes or impurities that are accumulated on the driving motor, and the temperature of the driving motor may be increased, thereby shortening the life of the driving motor. Furthermore, for maintenance or repair of the driving motor that is mounted in the body, the driving motor has to be removed from the body and this may increase the time and cost of use.
To overcome the shortcomings, the present invention provides an ash-collecting and exhaust device for a grain dryer to mitigate or obviate the aforementioned problems.